Kappa Delta Award paper. Tissue fluid pressures: from basic research tools to clinical applications

The two basic research tools developed to measure tissue fluid pressure (wick catheter) and osmotic pressure (colloid osmometer) have undergone extensive validation and refinement over the past 20 years. Using these techniques, basic science investigations were undertaken of edema in Amazon reptiles, pressure-volume relations in animals and plants, adaptive physiology of Antarctic penguins and fishes, edema in spawning salmon, tissue fluid balance in humans under normal conditions and during simulated weightlessness, and orthostatic adaptation in a mammal with high and variable blood pressures--the giraffe. Following and sometimes paralleling this basic research have been several clinical applications related to use of our colloid osmometer and wick technique. Applications of the osmometer have included insights into (a) reduced osmotic pressure of sickle-cell hemoglobin with deoxygenation and (b) reduced swelling pressure of human nucleus pulposus with hydration or certain enzymes. Clinical uses of the wick technique have included (a) improvement of diagnosis and treatment of acute and chronic compartment syndromes, (b) elucidation of tissue pressure thresholds for neuromuscular dysfunction, and (c) development of a better tourniquet design for orthopaedics. This article demonstrates that basic research tools open up areas of basic, applied, and clinical research.

Massive allograft replacement of hemiarticular traumatic defects of the elbow

Four elbow osteoarticular allografts were done for four patients as salvage procedures for unreconstructable elbow fracture malunions. With a mean follow-up of 60 months (range, 12 to 72 months) all elbows were stable, free of pain, and had mean motion of 130 degrees active flexion and 27 degrees of flexion deformity, 67 degrees pronation and 62 degrees supination (preoperative mean: 104 degrees flexion, 42 degrees flexion contracture, 20 degrees pronation, and 34 degrees supination). Complications occurred in two elbows. One had a deep infection necessitating graft removal and subsequent regrafting. The second had an olecranon osteotomy nonunion. Elbow allografting is recommended as a salvage procedure for massive posttraumatic articular defects, bone loss, or malunion when neither arthrodesis nor conventional arthroplasty is indicated.

Infections of the hand

Important developments in the past 10 years include the use of improved prophylactic antibiotics, anesthetic techniques, jet pulsatile lavage, closed irrigation techniques, postoperative therapy, and splinting. The basic principles of thorough debridement of necrotic and infected tissue and healing by secondary intention with elevation and splinting remain paramount in the treatment of the infected hand.

Intra-articular fractures of the basilar joint of the thumb

This article on intra-articular fractures of the basilar joint of the thumb discusses the biomechanical and treatment complexities of fractures involving the thumb carpometacarpal joint. This review focuses on the treatment of thumb carpometacarpal fractures and dislocations, consolidating current philosophy and rationale regarding operative and nonoperative treatment. Treatment recommendations are based upon principles established in previous clinical and biomechanical studies emphasizing fracture-specific modalities. Emphasis is placed on maintenance of articular congruity, fracture stability, early motion, and maximum return of function.

Ulnar nerve compression at the wrist

Two cases of compression of the ulnar nerve by ganglions in the distal ulnar tunnel are reported. The type of neurologic deficit (motor, sensory, or both) was helpful in predicting both the zone of nerve compression and the nature of the compressing lesion.

Elbow Flexion Contractures: Treatment by Anterior Release and Continuous Passive Motion

We treated three elbows with post-traumatic flexion contractures (mean contracture: 41°) by operative release and post-operative continuous passive motion rehabilitation.

Each elbow had been resistant to at least six weeks of conservative therapy. All patients complained of the residual deformity and some functional deficit. All patients, after failure of non-operative therapy, desired operative treatment.

At follow-up (mean 12 months), there was a mean post-operative contracture of 5°. Continuous passive motion is recommended as an adjunct to anterior release in patients with resistant elbow flexion contractures.

Lipoma of the flexor digitorum superficialis causing triggering at the carpal canal and median nerve compression

A lipoma in the carpal canal was associated with both triggering of the fingers at the level of the transverse carpal ligament and median nerve compression. We were unable to find a similar case reported in the English-language literature.

Internal vascularity of the scaphoid in cadavers after insertion of the Herbert screw

This article describes the effects of various operative exposures for insertion of the Herbert screw on the internal vascularity of the scaphoid. Vessels supplying the proximal 70% to 80% of the scaphoid were intact in all specimens except one, which had a combined palmar and dorsal. approach. Vessels supplying the tubercle and the distal 20%-30% were disrupted in five of 18 specimens undergoing the palmar approach. The palmar approach did not disrupt the significant dorsal blood supply, and the dorsal approach was safe provided care was taken to preserve the visible dorsal vascular leash.

The history of carpal tunnel syndrome

Carpal tunnel syndrome is the most frequently diagnosed, best understood and most easily treated entrapment neuropathy. During the first half of the 20th century, however, most patients with carpal tunnel syndrome were diagnosed as having compression of either the brachial plexus or thenar nerve motor branch of the median nerve. As late as 1950, only twelve patients with operative release of the transverse carpal ligament for idiopathic carpal tunnel syndrome had been reported. The delay in accurate anatomical localization of this compressive neuropathy can be attributed both to the confusion caused by the diverse manifestations of median nerve compression in the carpal tunnel, and to some interesting developments that altered early investigations in this area.

The History of Carpal Tunnel Syndrome

Carpal tunnel syndrome is the most frequently diagnosed, best understood and most easily treated entrapment neuropathy. During the first half of the 20th century, however, most patients with carpal tunnel syndrome were diagnosed as having compression of either the brachial plexus or thenar nerve motor branch of the median nerve. As late as 1950, only twelve patients with operative release of the transverse carpal ligament for idiopathic carpal tunnel syndrome had been reported. The delay in accurate anatomical localization of this compressive neuropathy can be attributed both to the confusion caused by the diverse manifestations of median nerve compression in the carpal tunnel, and to some interesting developments that altered early investigations in this area.

Carpal tunnel syndrome. A scientific basis for clinical care

The series of experimental studies reviewed in this article supports a classification of median nerve compression at the wrist into early, intermediate, advanced, and acute nerve compression. The findings correlate well with experimental studies on the pathophysiology of nerve compression. A patient-specific management approach is recommended based upon the clinical and electrophysiologic findings which can be correlated with previously demonstrated intraneural pathologic changes.

Ganglions of the wrist and digits: results of treatment by aspiration and cyst wall puncture

In a prospective study, 87 carpal and digital ganglions were aspirated, multiply punctured, and digitally ruptured. Fifty percent of wrists and digits were immobilized for 3 weeks and 50% were mobilized early. Mean follow-up was 22 months. Thirty-six percent (31/87) of all ganglions treated showed a successful outcome. Twenty-seven percent (16/60) of dorsal carpal, 43% (6/14) of palmar carpal, and 69% (9/13) of palmar digital ganglions did not recur. Immobilization significantly improved the results of treatment of dorsal carpal ganglions. Forty percent (12/30) of those in the immobilization group and 13% (4/30) of those in the early mobilization group had a successful outcome (p less than 0.05).

Carpal tunnel volume determination by magnetic resonance imaging three-dimensional reconstruction

Three-dimensional computer reconstruction of magnetic resonance images (MRI) of ten cadaveric specimens was used to determine carpal tunnel volume and carpal arch width. Magnetic resonance images-acquired data were compared with direct measurement of cadaveric carpal canal volume by means of a silicone-injection technique. Mean MRI three-dimensional reconstruction volume was 5.84 ml +/- 1.24 ml. Mean silicone-mold volume was 4.73 +/- 1.01 ml. A correction factor of 0.8161 was used to accurately calculate carpal tunnel volume from MRI-acquired data. There was no significant difference between calculated carpal tunnel volumes and silicone-mold volumes (p = 0.623), and there was a linear relationship between MRI-acquired volumes and silicone-mold volumes (correlation coefficient r = 0.97). Differences in MRI-volume determinations between observers were not significant (0.25 greater than or equal to p greater than 0.1). MRI three-dimensional reconstruction, a valid and reproducible technique for measuring carpal tunnel volume and dimensions, has considerable research potential for the evaluation of the relationship between the carpal canal and its contents before and after carpal tunnel release.

The biotechnology of hand and wrist implant surgery and rehabilitation

The earliest successful implants for restoration, alignment and function of finger joints and the wrist were made of organic silicones. In spite of initial improvement, the longterm complications of fracture, loosening and silicone synovitis have led to a search for better methods. Techniques currently under study are perichondrial grafting, the use of processed carbon implants and continuous passive motion rehabilitation.

Results of treatment of severe carpal-tunnel syndrome without internal neurolysis of the median nerve

Thirty-three hands (twenty-nine patients) had a release of the carpal tunnel without internal neurolysis for severe carpal-tunnel syndrome. All of the hands had increased values for two-point discrimination or thenar atrophy, or both. Twenty-three (89 per cent) of the twenty-six hands that had increased values for two-point discrimination and twenty-six (87 per cent) of the thirty hands that had an elevated result on Semmes-Weinstein testing had normal values at follow-up. Nine (90 per cent) of the ten hands that had weakness of the thenar muscles (grade-3 strength or less) regained grade-4 or 5 strength. Thirteen (65 per cent) of the twenty hands that had thenar atrophy regained normal muscle bulk. Eighteen (62 per cent) of the twenty-nine patients had complete resolution of symptoms and signs of compression of the median nerve. No significant difference was found between the results in this series of patients and those in a previously reported similar group of patients who were treated by release of the carpal tunnel combined with internal neurolysis of the median nerve.

Repair of severe muscle belly lacerations using a tendon graft

Fourteen patients with 58 severe forearm muscle belly lacerations had muscle repair using tendon grafts. At mean follow-up of 14 months, results of manual muscle testing (N = 58) were: grade 5, 42%, grade 4, 14%, grade 3, 9%, grade 2, 9%, grade 1, 12%, and grade 0, 15%. Mean grip strength of the injured extremity, in pounds per square inch, was 33.5 compared with 83.4 on the noninjured side. Tendon excursion and joint mobility were maintained, and there were no postoperative complications. Tendon grafting of severe muscle lacerations is an effective method to overcome extensive defects.

High-resolution magnetic resonance imaging of the wrist: normal anatomy

Magnetic resonance imaging (MRI) provided adequate depiction of carpal soft tissue structures in normal volunteers, as well as accurate anatomic correlation with cadaveric specimens. Using a high field strength system and surface coil techniques, the intricate anatomy of the wrist was best defined on long TR short TE images. However, from a practical view, T1 weighted images (TR 600 ms, TE 25 ms) were most useful because of short imaging times, satisfactory image quality, and the absence of motion artifacts. The coronal plane provided the clearest definition of important structures. Potential diagnostic limitations exist due to the inability of MRI to clearly delineate articular cartilage, joint capsules, and small interosseous ligaments. The presence of intra-articular fluid in both living subjects and cadaveric specimens, however, allowed for fine depiction of these structures on T2 weighted images.

Fractures of the carpus, excluding the scaphoid

Carpal bone fractures comprise an important group of injuries that present difficulties in both diagnosis and treatment. These fractures may be missed for the following reasons: physician's low index of suspicion, the carpal bones' irregular contours and degree of overlap on radiographs making the fractures difficult to visualize, and the common occurrence of concomitant fractures of neighboring metacarpals, distal radius, or scaphoid, which misdirects the examiner. A high index of suspicion with careful clinical examination and elicitation of point tenderness is key to making the correct diagnosis (Fig. 14). Swelling, loss of motion, deformity, and crepitus are often minimal and are not reliable in distinguishing carpal fractures. Specific radiographic projections, tomograms, computerized tomographic scans, or bone scans are often required and should be considered in any wrist injury where the diagnosis is in question. A greater awareness of the fracture types, methods of diagnosis, and choices of treatment is essential for optimal management of these injuries.

Femoral anteversion. A clinical assessment of idiopathic intoeing gait in children

Hip rotation in extension and flexion was studied in 23 patients with idiopathic intoeing gait. In extension all the hips had markedly increased medial rotation and limited lateral rotation, fulfilling the criteria of excessive femoral anteversion. In flexion, however, rotation varied widely; in one group of patients medial rotation remained greater than lateral, but in the second group lateral rotation was equal to or greater than medial. CT scans showed that the hips in the first group were significantly more anteverted than those in the second. Clearly measurement of hip rotation in extension alone does not provide a dependable indication of femoral anteversion in children with intoeing gait; rotation in flexion also needs to be measured.

Obesity and decreased femoral anteversion in adolescence

The degree of femoral anteversion in a group of obese adolescent children and a group of adolescent children of normal weight was determined by either magnetic resonance imaging or computerized axial tomography. Compared with the children of normal weight, the obese children showed a significantly reduced angle of femoral anteversion. Increased biomechanical forces generated across the hip joint of obese children leads to increased remodeling of the femoral neck. This may account for the association of slipped capital femoral epiphysis, reduced femoral anteversion, and obesity in the adolescent population.

The association of femoral retroversion with slipped capital femoral epiphysis

We examined twenty-five patients who had a unilateral or bilateral slip of the capital femoral epiphysis and determined the degree of anteversion of the thirty-nine involved hips with computerized axial tomography. Thirteen patients (eighteen hips) were seen at the time of the original diagnosis (Group I), and twelve patients (twenty-one hips) were seen one to seven years after operative treatment (Group II). The mean amount of anteversion for all of the involved hips was +1.0 +/- 8.2 degrees. The mean amount of anteversion for the Group-I hips was -0.7 +/- 7.4 degrees and the mean amount for the Group-II hips was 2.5 +/- 8.7 degrees. The mean amount of anteversion for the hips in both Groups I and II was less than the predicted mean amount for individuals of the same age. The mean amount of anteversion of the unaffected hips of our patients who had a unilateral slip was +6.3 +/- 8.2 degrees. The amount of internal rotation of the hip in extension exceeded the amount when it was in flexion in all of the patients. A decreased angle of femoral anteversion appears to be specifically associated with the development of slipped capital femoral epiphysis. The mechanical forces that act across the proximal femoral physis may be altered by this rotational abnormality, and this may lead to an increased shear stress that ultimately causes failure of the growth plate.

Carpal tunnel syndrome. An evaluation of the provocative diagnostic tests

In order to evaluate the usefulness of provocative tests (wrist-flexion test, nerve-percussion test, and tourniquet test) in the diagnosis of carpal tunnel syndrome, the results of provocative testing were evaluated in a group of patients (sixty-seven hands) with electrodiagnostically proved carpal-tunnel syndrome and in a group of fifty control subjects. The sensitivity and specificity of each test were calculated. The wrist-flexion test was found to be the most sensitive while the nerve-percussion test, although least sensitive, was most specific. The tourniquet test was quite insensitive and not very specific, and should not be used as a routine screening test in the diagnosis of carpal tunnel syndrome.